// if is edited a single pot template from tagDiv Standard Pack
 <?php if (!empty($td_mod_single->td_post_theme_settings['td_subtitle'])) { ?>
                    <p class="td-post-sub-title"><?php echo $td_mod_single->td_post_theme_settings['td_subtitle'];?></p>
                <?php } ?>


// another method that can be used outside of the single template is:
                <?php
                $meta = get_post_meta(get_the_ID(), 'td_post_theme_settings', true);

                if (!empty($meta['td_subtitle'])) {
                    echo esc_html($meta['td_subtitle']);
                }
                ?>